The heavy duty trucking industry is seeking alternative suspension system solutions that offer a better ride performance than-conventional mechanical leaf suspensions, while maintaining or improving handling performance. Light to medium heavy suspensions, i.e. suspensions for up to approximately 14,000 pounds, have utilized air suspension configurations that provide improved ride performance, but which have marginal handling performance.
One solution for heavy front suspensions, i.e. suspensions for up to approximately 20,000-23,000 pounds, is the use of an independent front suspension. The independent front suspension has good ride and handling performance, however, this type of suspension is complex, heavy, difficult to package in a truck, and is cost prohibitive. Another solution utilizes a multi-link air suspension, which provides good ride and handling performance. However, this type of system is also heavy, complex, and expensive.
Trailing arm air suspensions offer a reasonable compromise between cost and performance, however, these suspensions can exhibit excessive brake dive. Excessive brake dive can cause the suspension to hit bump stops during severe braking applications. Repeated contact between suspension components and the bump stops can adversely affect suspension performance and the overall wear life of the suspensions components.
Thus, there is a need for a trailing arm suspension for a heavy duty vehicle that does not experience the adverse effects of excessive brake dive, and which overcomes the other above-mentioned difficulties in the prior art.